1. Field of the Invention
This invention is related to a process for producing carbon black. More specifically, this invention provides a process for producing a relatively coarse, highly structured carbon black having a large relatively uncontaminated surface area.
2. Description of the Prior Art
In conventional processes of making carbon black, it has been difficult to achieve and control a relatively high ratio of aggregate particle size to surface areas; that is, in manufacturing a carbon black particle with a large surface area, the particle size became smaller. Prior art methods that increase surface area by hollowing out the aggregate carbon black particle, without decreasing significantly the aggregate particle size, resulted in excessive etching of the surface of the aggregate particle.
Also, in conventional processes of making carbon black, it has been difficult to achieve consistently a relatively uncontaminated surface because of an inability to clean the surface of the carbon black particle due to the presence of contaminants in the effluent gases. Even when special care is taken in the processes of the prior art to make a relatively clean surface, it was found to be economically unattractive because of low yields.
U.S. Re. Pat. No. 19,664 by Damon teaches modifying the properties of commercial carbon black by subjecting it to a controlled oxidation in such a manner as to increase its oxygen content. Damon discovered that more efficient and accurate results may be achieved by subjecting carbon black, which has been produced under conditions resulting in maximum yield, to a supplementary and separate oxidizing treatment under controlled conditions. In carrying out his invention, Damon secured satisfactory results by subjecting commercial carbon black to heat within definite limits and agitation in the presence of atmospheric oxygen. U.S. Pat. No. 3,184,290 by Jordan relates to a novel, highly conductive carbon black produced from those hydrocarbonaceous tars or residues which have high contents of materials known generally in the art as asphaltenes or carbenes. Jordan teaches the pyrolysis of asphaltenes which have been treated with chemical oxidizing agents, particularly nitric acid and nitric oxides. U.S. Pat. No. 3,607,064 by Dollinger et al. illustrates a method of adding property-controlling additives to the reaction zone in carbon black production. More specifically, Dollinger et al. discloses introducing with the pre-heated make-oil a property-effecting mixture having a melting point less than that temperature to which the make-oil is preheated. U.S. Pat. No. 3,725,103 by Jordan et al. relates to a new type of carbon black products prepared by a furnace process which, while not aftertreated, have physical properties which render the blacks different from any other conventionally known types of grades of carbon blacks. U.S. Pat. No. 3,787,562 by Heller et al. discloses a carbon black product which is employed as pigments in rubber, paints, lacquers, and plastics. U.S. Pat. No. 3,867,513 by Krejci teaches a method and apparatus for introducing charge oil and a dispersant as a mixture into a carbon black reactor to establish two zones of charge oil at different entrance velocities into the reactor. U.S. Pat. No. 3,952,087 by Antonsen et al. relates to a process for preparing carbon blacks by the incomplete combustion of hydro-carbonaceous feedstocks wherein the resultant blacks have higher structure characteristics than the carbon blacks normally prepared from the feedstocks. U.S. Pat. No. 3,992,218 by Suetsugu et al. discloses an industrially advantageous preparation of a coloring agent having excellent characteristics by using furnace carbon black as the coloring component. U.S. Pat. No. 4,013,759 by Giet teaches a process which comprises the incomplete combustion of at least one hydrocarbon having at least one ethylenical bond, preheated to a temperature clearly higher than its critical temperature. The recovered carbon black may be used in the manufacture of dry cells. U.S. Pat. No. 4,018,878 by Reynolds discloses an oil furnace process for the production of tread grade rubber reinforcing carbon black which is modified in respect of the manner in which a carbon black producing feedstock oil is introduced into the cracking zone so as to facilitate the formation of carbon black of requisite structure characteristics having improved particle size distribution. U.S. Pat. No. 4,031,189 by Gemmeke et al. teaches a process for preparing a composition high in carbon content and containing only a small amount of ash, nitrogen and sulfur by the conversion of a hydrous carbon sludge or carbon pellets. U.S. Pat. No. 4,061,719 by Shallus et al. discloses a process of conductive carbon black for use in depolarization masses in dry batteries. U.S. Pat. No. 4,075,156 by Johnson teaches a production of non-carcinogenic large particle carbon black. U.S. Pat. No. 4,093,421 by Jerkins illustrates an injection assembly for introducing a plurality of laterally spaced sprays of a normally liquid hydrocarbon feedstock into the cracking zone of a carbon black furnace. U.S. Pat. No. 4,101,639 by Surovikin et al. relates to methods of producing carbon black and may be used for the production of various types of carbon blacks as well as for the production of technical grades of hydrogen obtained as a gaseous by-product. Finally, U.S. Pat. No. 4,279,880 by Giet teaches an acetylene black having both high electrical conductivity and high absortive capacity for liquids. None of the foregoing prior art teach or suggest the novel furnace process of this invention for producing a relatively coarse, highly structured carbon black having a large surface area.